Answer:
The pitching speed of your friend is 33.20 m/s
Explanation:
<em>Lets explain how to solve the problem</em>
Your friend throw the ball horizontally that means the vertical initial
component of velocity is zero (
).
The ball is thrown from a height 4 meters above the ground.
The height ![h=u_{y}t+\frac{1}{2}gt^{2}](https://tex.z-dn.net/?f=h%3Du_%7By%7Dt%2B%5Cfrac%7B1%7D%7B2%7Dgt%5E%7B2%7D)
<u><em>Remember:</em></u> the height is negative value because its below the point of
thrown (initial position)
h = -4 m ,
and g = -9.8 m/s²(downward)
<em>Substitute these values in the rule above</em>
⇒ ![4=0-\frac{1}{2}(9.8)t^{2}](https://tex.z-dn.net/?f=4%3D0-%5Cfrac%7B1%7D%7B2%7D%289.8%29t%5E%7B2%7D)
⇒ -4 = -4.9t² (multiply both sides by -1)
⇒ 4 = 4.9t² (divide both sides by 4.9)
⇒ 0.81633 = t² (take √ for both sides)
⇒ <em>t = 0.9035</em>
Then the time of the ball to land on the ground is 0.9035 seconds
The range of the ball on the ground is 30 m
The range
, where
is the horizontal
component of the initial velocity
R = 30 meters and t = 0.9035
⇒
(divide both sides by 0.9035)
⇒
m/s
<em>The pitching speed of your friend is 33.20 m/s </em>